Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor. The rotor is coupled to the nacelle and includes a rotatable hub having one or more rotor blades. The rotor blades are connected to the hub by a blade root. The rotor blades capture kinetic energy from wind using known airfoil principles and convert the kinetic energy into mechanical energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
The particular size of the rotor blades is a significant factor contributing to the overall capacity of the wind turbine. Specifically, increases in the length or span of a rotor blade may generally lead to an overall increase in the energy production of a wind turbine. Accordingly, efforts to increase the size of rotor blades aid in the continuing growth of wind turbine technology and the adoption of wind energy as an alternative and commercially competitive energy source. Such increases in rotor blade size, however, may impose increased loads on various wind turbine components. For example, larger rotor blades may experience increased stresses at the connection between the blade root and the hub, leading to challenging design constraints, both characterized by extreme events and fatigue life requirements.
Many rotor blades utilize root bolt inserts to reduce the stresses at the blade root-hub interface. Such root bolt inserts can be produced using a variety of processes, including but not limited to pultrusions. A common approach is to infuse root bolt inserts with fabrics and rovings to provide a laminate substrate by which later infusions can be used to effectively bond the insert into the blade root laminates. Round, square, trapezoidal, or similar profiles may be used, though the number of root bolt inserts required often leaves a gap between inserts that must be filled with a mixture of glass and resin. This process entails cutting very small strips of glass and placing the strips manually in the blade root and then using a typical vacuum infusion process. Such a process can be labor-intensive and often results in poor laminate quality of the laminates between the root bolt inserts.
Thus, there is a need for an improved rotor blade root assembly that addresses the aforementioned issues. Accordingly, a rotor blade root assembly that reduces labor cycle time and improves laminate quality would be advantageous.